Taiwanese patent application No. 84101011 (Certificate No. Invention 106808) discloses a ferrofluid sink/float separator for separating a mixture of aluminum particles, zinc particles and copper particles, which simulates a typical metal scrap from dumped cars. The zinc-containing articles collected from dumped cars or other sources are generally electroplated with multiple layers of copper/nickel or copper/nickel/chromium. Currently, there is no cost-effective method for recycling the zinc and the copper/nickel or copper/nickel/chromium electroplating layers (hereinafter the "multiple layers of copper/nickel or copper/nickel/chromium" will be referred to as a nickel/copper electroplating layer) of the zinc-containing articles.